Geometry and Trigonometry — one screen
≈15% of Math · 5–7 questions · the smallest domain, and the reference sheet does half of it for you.
What the reference sheet gives you
Areas and circumferences of circles, areas of rectangles and triangles, volumes of prism, cylinder, sphere, cone and pyramid, the Pythagorean theorem, the two special right triangles, and the fact that a circle has 2π radians.
What it does not give you — and what is therefore worth knowing cold:
- Angles on a line sum to 180°, round a point to 360°, in a triangle to 180°
- An exterior angle equals the sum of the two opposite interior angles
- Parallel lines: corresponding angles equal, alternate angles equal, co-interior sum to 180°
- Similar triangles have equal angles and proportional sides
- SOH-CAH-TOA, and sin(x°) = cos(90° − x°)
- The circle equation (x − h)² + (y − k)² = r²
- Arc length = (θ/360) × circumference; sector area = (θ/360) × area
- An inscribed angle is half the central angle on the same arc
Special right triangles
| Triangle | Sides |
|---|---|
| 45°–45°–90° | x, x, x√2 |
| 30°–60°–90° | x, x√3, 2x |
Common Pythagorean triples: 3-4-5, 5-12-13, 8-15-17, and their multiples.
Scaling
Lengths scale by k. Areas scale by k². Volumes scale by k³. Every year there is a question that turns on this.
Radians
Where points go
- Using the diameter where the formula wants the radius.
- Forgetting to square or cube the scale factor.
- Taking sine where the sides given call for cosine or tangent.
- Assuming a diagram is to scale — it is not, unless it says so.
- Leaving an answer in degrees when the question asked for radians.
Educerie · written from the published College Board Assessment Framework for the Digital SAT Suite (Math, Geometry and Trigonometry). Original text. Last reviewed 12 September 2026.